Employee Payroll Model

Technical notes

The abstract Employee class stores shared employee information and declares calculateSalary.
FullTimeEmployee calculates base salary plus bonus. PartTimeEmployee calculates hours worked multiplied by the hourly rate.
EmployeeTestDrive loops through an Employee array. Each object uses its own salary calculation through runtime polymorphism.

Compile and run

With JDK 17 or newer installed, open a terminal in the extracted project folder.

javac -d out src/Module1/*.java
java -cp out Module1.EmployeeTestDrive

The demo calculates salaries for four sample employees using a base salary plus a bonus, or hours worked multiplied by the hourly rate.

Source code

src/Module1/Employee.java

/**
 *  Create a program that models different types of employees using inheritance and polymorhispm.
 * 
 * 1.Parent Class: Employee - abstract class (cannot be instantiated)
 * 	Fields: String name 
 * 			int id
 * 			double baseSalary
 *	Constructor to initialize all fields
 *	Methods:
 *		doubble calculateSalary() - returns baseSalary
 * 	Constructor to initialize all fields
 * Method: 
 * 	double calculateSalary() - returns baseSalary
 * 	void displayInfo() - prints employee details
 * 
 * 2.	Subclass: FullTimeEmployee
 * 
 * Additional Field:
 * 		double bonus 
 * Override:
 * 		calculateSalary() - baseSalary + bonus
 * 
 * 3. Subclass: PartTimeEmmployee
 * Additional field:
 * 	int hoursWorked
 * 	double hourlyRate
 * 
 * Override:
 * 		calculateSalary() - hoursWorked * hourlyRate
 */

package Module1;


public abstract class Employee {
		
		//Attributes
		 String name;
		 int id;
		 double baseSalary;
		 
		 //Constructor
		 public Employee (int id,String name, double baseSalary) {
			 this.id = id;
			 this.name = name;
			 this.baseSalary = baseSalary;
			 
		 }
		 //Abstract method (polymorphism)
		public abstract double calculateSalary();
		 
		 //Common method
		 public void displayInfo() {
			 System.out.println(
					 "ID:" +id +
					 ",Name:" + name +
					 ", Salary: " + calculateSalary());
		 
		 
		
	}

}

src/Module1/FullTimeEmployee.java

/**
 * 
 */
package Module1;

/**
 * 
 */
public class FullTimeEmployee extends Employee {

	double bonus;
	
	//constructor
	public FullTimeEmployee(int id,String name, double baseSalary,double bonus) {
		super(id, name, baseSalary);
		this.bonus= bonus;
		
	}
	
	@Override
	public double calculateSalary() {
		return baseSalary + bonus;
	
	}

}

src/Module1/PartTimeEmployee.java

/**
 * 
 */
package Module1;


public class PartTimeEmployee extends Employee {

	
	int hoursWorked;
	double hourlyRate;
	
	//constructor
	public PartTimeEmployee(int id,String name, int hoursWorked, double hourlyRate) {
		super(id, name, 0); //baseSalary not used for part- time
		this.hoursWorked = hoursWorked;
		this.hourlyRate = hourlyRate;
		
	}
	
	@Override 
	public double calculateSalary () {
		 return hoursWorked * hourlyRate ;
	
	}

}

src/Module1/EmployeeTestDrive.java

/**
 * 
 */
package Module1;

/**
 * 
 */
public class EmployeeTestDrive {

	
	public static void main(String[] args) {
		//Polymorphism: parent refernce, child objects
		Employee[] employees = new Employee [4];
		
		
		employees[0] = new FullTimeEmployee(101,"Alice",50000,500);
		employees[1] = new PartTimeEmployee(102,"Bob",80,150);
		employees[2] = new FullTimeEmployee(103,"John" , 600 , 150);
		employees[3] = new PartTimeEmployee(104, "Annie", 40, 60);
		
		//Display employee details
		for(Employee emp : employees) {
			emp.displayInfo();
			}
		

	}

	}